That cost is simple. Most cellular connections are not all that clear. Even when they are pristine, the person on the other end of the connection often sounds a bit distant. This forces the user of the phone to speak at a magnified volume. This forces the people in their vicinity to listen to their conversation. And sadly, most cell phone conversations aren't all that interesting.

For instance:

"Hello?…Yeah, I'm just heading out of Sever…I don't know, I fell asleep half-way through the lecture…The Bow?…I guess so…Look, I just have to pick up my laundry and then I'll be home…Okay, see you then."

Or:

"Hello?…I can hardly hear you…Yeah, Eliot dining hall…With Jess and Mike…Okay, I'll e-mail you later."

Besides the excruciating anguish of asinine exchanges such as these, there is of course the ring factor. Ringing is a form of auditory stimulus specifically designed to capture the attention of nearby humans. As such, it is inherently irritating. And, no, a Beethoven ring isn't an improvement. We should not be subjected to such irritation everywhere we go.

Of course, as was warned, much of this was redundant. We all know how annoying cell phones are. The point here is that this is a college. None of us are running multi-national corporations just yet. Lamont Library has posters reminding people to turn off their phones in the reading room. The fact that such posters are necessary is mind-boggling. Do we also need posters reminding people not to defecate in the stacks? What is wrong with a person that they would bring a ringing phone into a library?